Different designations on the same material
There are different ergonomic and orthopedic pillow brands out there (Royal Rest, Core, Sissel and Tempur) and they are alla made of material called flexible polyurethane foam (PUR), which is a very malleable, flexible material and antibacterial or allergy neutral.
The cellular structure of the material provides more even relief and has good sanitary properties. It is therefore well suited when the purpose requires special adaptation or variation in hardness and weight. Other everyday terms also occur, such as foam plastic.
Difference between memory foam and classic foam
Viscoelastic foam, also called memory foam, responds to temperature fluctuations where the cold makes it solid and heat makes it softer, which makes it easier to be affected by pressure. Highly elastic foam (HR), also called classic foam or traditional foam material, reacts very little to temperature and provides constant equal pressure-relieving support.
The hardness of the material
Flexible polyurethane can be manufactured with different hardness / strength: from super soft to very rigid materials. Both materials, viscoelastic and high density foam, which are made by a continuous foaming process called block casting, can vary by up to +/- 15% in strength, even if they are made from the same foam board. This can make up to 30% difference in firmness between individual pillows / mattresses and creates a different feeling, even when it comes to the same brand and lot.
Aging or yellowing foam material
Polyurethane turns yellow when exposed to the sun’s UV light. It has no effect on the properties of the material in general, but in the long run it accelerates the aging process in the material. The aging process consists of the material structure’s cell structure becoming fragile and stiffer, which in the long run has a negative effect on the pressure-relieving function.
Polyurethane has a high energy content and is suitable for energy recovery when carried out at a plant that is approved for waste incineration.
Antibacterial, allergy neutral and hygiene
Flexible polyurethane, both inert and highly elastic, is an allergen-neutral material used in many skin-friendly products in many areas, and is often used for sleep-ergonomic products such as mattresses and pillows. It is a neutral material, which means that mites or bacteria can not feed on it. The material is water-resistant, but to varying degrees sensitive to machine washing, as the product itself is exposed to mechanical impact (machine) and can be torn to pieces, but in most cases they can be hand-washed and self-dried.